Crown block for well-drilling apparatus



July 22 1924.

15 02161 C. C. SCHARPENBERG ET AL CROWN BLOCK FOR WELL DRILLING APPARATUS Filed Nov. 2, 1923 Imam e are manna, or BAKERSFIELD, AND LEnoY e. earns, or urine, came, assrenons 'ro srannann 11. COMPANY, or sen mncrsco, GALI- u. e a COOTION or CALIFORNIA.

CROWN BLUCK FOR WELL-DRILLING- APPARATUS.

Application filed November 2, 1923. Serial No. 672,408.

drilling a paratus, and, in particular, to

crown bloc s, an assembly of sheaves mounted on the derrick top and carrying the several operating ropes. I

One object of our invention is to be able to use sheaves of large diameters, say for example, to inches instead of the usual 24: to 36 inches. Another object is to so an arrange these relatively large sheaves thatthe ropes will lead on and off more nearly strai ht with the groove, having little or I no si e pressure on the groove flanges.

Another object is to be able to hoist the 25 travelin block higher or closer to the crown-b cck.

Another object is to provide a crownblock having, large bearing surfaces. Another object is to include in the sheave asso sembly a sand sheave and a crown sheave, so arranged as to lead their respective lines or ropes very near the center of the der-v rick, at the same time that the casing sheaves support the traveling block also 35 very close to the center of the derrick.

Another object is to attain these several vantages without materially changing the construction or size of the top of the present.

. standard derrick. a The advantage of the large diameter sheaves is to minimize the stresses imposed upon the ropes by the smaller diameter sheaves. The advantage of leading the ropes on and off as nearly straight with as the groove as possible, that is, to reduce the fleet angle of the rope to a minimum is that by avoiding side pressure on the flanges of the rope groove, wear is prevented on both the rope and flanges. an In drillin deeper wells and in using longer trave ing blocks, hooks, etc., it has become necessary to raise the traveling blocks to a greater height. This has made it to build higher derricks. But

by our arrangement we are able to gain this extra height or lift, without going to the expense of the higher derrick with its greater cost and danger.

With larger bearing surfaces for the sheaves, the bearings will give longer and more reliable service, due to less wear. With regard to the'sand sheave and the crown sheave, it is obvious that when the sand line is bein used in the well, it is desirable that to line travel perpendicularly from the inside of the well to the sand sheave, which makes it necessary to be able to place said sheave so that it leads as near- 1y as possible from the center of the derrick top, the exact position depending upon the exact location of the well. The same holds true of the crown sheave and its drilling line. Alsothe traveling block should han under the center of the derrick top and this is efi'ected by the arrangement of the casing sheaves which support it.

With these objects inview our invention consists in the novel crown-block which we shall now fully describe by reference to the accompanying drawings in which Fig. 1 is a plan view of our improved crown block; Fig. 2 is a side elevation of the same in position, on the top of the derrick, the traveling block and the various ropes and lines being indicated by dotted lines.

The structural frame of the crown-block comprises the upper longitudinal beams 1, the lower longitudinal beams 2, and the intervening cross beams 3. The .shapes, the fittings and the tying together of these members may be according to any good practice, but as these particulars form no part of our invention, we have not deemed it necessary to illustrate them.

The frame thus formed is mounted on sills 4 on the top 5 of the derrick 6, as seen in Fig. 2.

Mounted upon the upper beams 1, is a shaft, Figs. 1 and 2; and upon the lower beams 2 is mounted a shaft 8, the two shafts being substantially parallel and lying in different vertical planes. On the upper beams 1 is also mounted a shaft 9 lying in a vertical plane on one side "of thevertical planes of the shafts 7 and 8; and upon the lower beams 2 is mounted a, shaft 10 lying in a vertical plane on the other sides of the verticalpl of said shafts 7 and 8.

All of these shafts are secured to the beams by 'any suitable means and for the sake of illustration merely, we have herein shown the U-clips 21.

The usual sheaves of a crown-block assembly comprise a plurality of easingsheaves, say, for example, five in number, a

sand-sheave, and a crown-sheave.

ed on the shaft 9. All these sheaves freely rotate upon their shafts, suitable lubrication being provided by any convenient means not shown in the drawings. By reference to Fig. 1 it will be seen that the successive lateral relation of the sheaves is as follows :the first upper casing-sheave; the first lower casing-sheave; the second upper casing-sheave; the sand sheave; the crown sheave; the second lower casing-sheave; and the third upper casing-sheave, and all said sheaves overlap in the direction of the center of the block and of the derrick top. This results in centrally suspending the traveling.- block, indicated diagrammatically in Fig. 2 by the dotted circle 14, said block being as usual carried by the lines 15 from the five casing-sheaves 11. At 17 is indicated the line to the calf-wheel, and at 16.the line to the draw works, which may be guided by a transversely mounted guide sheave 17'. From the outer side of the sand-sheave 13 hangs the line 19 to the sand reel; while from the inner side of said sheave the other fallofsaid line, indicated by 19', extends down approximately centrally of the derrick top and directly above the well. From the outer side of the crown-sheave 12v extends the drilling line 18, and from the inner side of said crown-sheave, the other fall of the drilling line indicated by 18 hangs directly above the well.

It will now be seen that by this arrangement of the sheaves, the ropes and lines will lead on and off more nearly straight with the grooves, leaving little or no side pressure on the groove flanges and imposing less stress upon the rope strands. Also that by apportioning or dividing the sheaves into different planes horizontally as well as vertically, thus producing what may be termed a double-deck crown block, it is possible to centrally condense them by overlapping their paths of rotation, and still keep them close together laterally, without regard to the width of their journals. Thus their bearing or journal surfaces on their shafts may be made much wider or more extensive and therefore more durable than would be possible if the sheaves were all placed hub to hub. And moreover, this arrangement permits us to use sheaves of greater diameter than is customary and thus reduce the stresses on the ropes. By our arrangement it is also possible to raise the traveling block to a greater height without having to build the derrick higher.

We claim:

1. A crown-block for well-drilling apparatus, comprising a supporting frame; a pair of substantially parallel shafts carried by said frame in different planes both horizontally and vertically; and a plurality of casing sheaves supported by and apportioned between said shafts, the sheaves of one shaft overlapping those of the other shaft.

2. A crown-block for well-drilling apparatus, comprising a supporting frame; a pair of substantially parallel shafts carried by said frame in different planes both horizontally and vertically; a plurality of casing sheaves supported by and apportioned between said shafts, the sheaves of one shaft alternating with and overlapping those of the other shaft.

3. A crown-block for well-drilling apparatus, comprising a supporting frame; a air of substantially parallel shafts carrie by said frame in difierent planes both horizontally and vertically; a plurality of easing sheaves supported by and apportioned between said shafts, the sheaves of one shaft overlapping those of the other shaft; a second pair of substantially parallel shafts carried by the frame one on each side of and parallel with the first pair; and sheaves supported by said second pair of shafts and overlapping said casing sheaves.

4. A crown-block for well-drilling apparatus, comprising a supporting frame; a pair of substantially parallel shafts carried by CHARLES C. soHARPEN ERG. 7 LEROY c. GATES. 

